Telescoping boom actuating mechanism



July 20, 1954 H. A. OLDENKAMP TELESCOPING BOOM ACTUATING MECHANISM 2 Sheets-Sheet l Filed July l2, 1950 19K Nm, .w bwl QN s T A S low wm #L w.

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. Edin July 20, 1954 H, A. OLDENKAMP TELESCOPING BOOM ACTUATING MECHANISM 2 Sheets-Sheet 2 Filed July 12, 1950 INVENTOR.

Patented July 20, 1954 TELESCOPING BOOM ACTUATING MECHANISM Henry A. Oldenkamp, Valhalla, N. Y., assignor to The Warner & Swasey Company, Cleveland, Ohio, a corporation of Ohio Application July 12, 1950, Serial No. 173,276

Claims.

This invention relates to a telescoping boom construction, and more particularly to such construction in combination with the actuating mechanism for the extensible and retractable member of the boom.

The telescoping boom construction embodying the invention is that type of boom which is used in a multi-purpose construction machine capable of performing trenching, digging, grading and other similar operations, and wherein the extensible and retractable member of the boom mounts at its outer end a suitable tool for the particular operation being performed.

Heretofore in booms of this type longitudinal movements have been imparted to the extensible and retractable boom member by a power mechanism, such as a hydraulic motor of the reciprocating type and wherein the piston rod is directly connected to the extensible member of the boom. The direct connection of the piston rod to the extensible member of the boom necessitates piston movement and cylinder length coextensive with the longitudinal movement of the extensible member.

An object of the present invention is to provide a boom of the type referred to wherein the extensible member telescopes within a fixed member and has longitudinal inward and outward movements imparted thereto by a power operated actuating mechanism or device, such that the movement producing part of said mechanism or device need travel only a fractional part of the actual travel movement of the extensible member of the boom.

Another object is to provide a boom construction wherein the power operated actuating mechanism or device for the extensible member of the boom is located internally of the boom and has an operative connection between the movement producing part of the mechanism or device and the extensible member of the boom, such, that movement of said part is fractional with respect to the actual movement imparted to the extensible member of the boom.

Another object is to provide in a boom of the type referred to actuating mechanism for moving the extensible member of the boom and which mechanism is relatively short in length as compared to the length of the extensible member, whereby the amplitude of the extending movement of the extensible member may be greatly increased.

A more specific object is to provide a boom construction and actuating mechanism as referred to in the previous objects and wherein, if the actuating mechanism is of the hydraulic cylinder and piston type, the length of piston movement and the length of cylinder may be greatly shortened in relation to the extensible and retractable movements of said boom member.

Further and additional objects and advantages not hereinbefore referred to will become apparent hereinafter during the detailed description of an embodiment of the invention which is to follow and which embodiment is illustrated in the accompanying drawing, wherein,

Fig. 1 is a side elevational View of a portion of a multi-purpose construction machine showing the telescoping boom mounted thereon and with the extensible member of the boom in extended position.

Fig. 2 is a fragmentary view somewhat similar to Fig. 1 but showing the extensible member of the boom in fully retracted position.

Fig. 3 is a transverse sectional view through the extensible member of the boom taken substantially on line 3--3 of Fig. 1 looking in the direction of the arrows.

Fig. 4 is a longitudinal sectional view taken through the boom on line 4 4 of Fig. 3 looking in the direction of the arrows and showing the extensible member of the boom in fully retracted position.

Fig. 5 is a View similar to Fig. 4 but showing the extensible member of the boom in extended position and also showing both the xed boom member and the extensible boom member broken away so as to shorten the view.

Fig. 5a is a detached detail sectional view showing the manner in which the actuating cables are connected to the inside of the extensible member of the boom.

Fig. 6 is a transverse sectional view through the boom and is taken substantially on line 6 6, of Fig. 5 looking in the direction of the arrows, and

Fig, 7 is a detached top plan view of the actuating mechanism shown in Figs. 4 and 5, with parts broken away to shorten the view.

The multi-purpose construction machine shown in Figs. 1 and 2 comprises a supporting platform III which, in this instance, is illustrated as mounted upon a vehicle chassis. The platform Iil has mounted on it a turntable II movable to any desired angular position. The turntable II mounts a cab and a frame I2 provided with upstanding trunnion supports I3. The fixed boom member I4 is mounted for rotative movement on its longitudinal axis in a circular housing I5 and said housing I5 is mounted on trunnions I6 carried by the supports I3 wherefore the boom may have raising and lowering movements imparted thereto as well as said rotative movements. Inasmuch as the construction thus far explained forms no part of the present invention and is well known in the art further reference thereto is unnecessary.

The boom construction embodying the invention comprises the fixed boom member I4, previously referred to, and the extensible boom member I1 which telescopes inwardly and outwardly of the fixed member.

Referring particularly to Figs. 3 and 6, the construction of the boom members will now be explained. The xed boom member Hl is triangular in cross section and is formed of longitudinally extending tubular supports i8 arranged at the three corners or angles of the triangle and to which are welded or otherwise secured plates i3. In this way an extremely rigid and strong structure is provided.

The plates i9 are provided with spaced openings 20 to lighten the boom and also to provide access to the interior of the boom for servicing, adjusting or maintenance purposes. The inner end of the boom member lli is closed by a plate 2| as indicated at the left hand end of Figs. 4 and 5. The outer end of the boom member I4 has secured to it a ring plate 22 through which projects the extensible member Il of the boom. The plate 22 mounts a trunnion 23 for a roller 2li and said trunnion has a stem portion projecting through an opening in the ring plate and into the upper tubular support i8. The roller 24 has a concave circumference for a purpose later to be explained. The plate 22 also supports at the lower corners of the member ill trunnions 25, 23, 21 and 28 which support, respectively, rollers 29, 33, 3i and 32, the purpose of which will later be explained.

The extensible boom member il is formed simila-rly to the fixed boom member I4, that is, it is triangular in cross section and at its three corners has tubular longitudinally extending supports 33 which have secured thereto by welding or other suitable means plates 3ft which are provided with spaced openings 35 similar to the openings 2S in the fixed boom member.

Referring particularly to Fig. 3, it will be seen that the concave circumference of the roller 24 engages the arcuate outer surface of the uppermost tubular support 33 of the extensible boom member Il. Also it will be noted that the rollers 2S and and 3l and 32, respectively, engage the tubular supports 33 at the lower side of the extensible boom member, said pairs of rollers engaging the tubular supports at right angles to each other.

The rollers carried by the xed boom member l!! function to stabilize and make smooth the inward and outward movements of the extensible boom member il at the outer end of the fixed boom member. rIhe inner end of the extensible boom member l'i is supported in the fixed boom member iii by means of rollers 36 engaging the interior of the fixed boom member and mounted in trunnions secured in the tubular supports 33, said rollers 36 having concave circumferences interntting the arcuate exteriors of the respective tubular supports IS of the fixed member. It will thus be seen that the extensible boom member is supported relative to the fixed boom member by spaced sets of rollers, one set carried by the fixed boom member and the other by the extensible member, thus assuring free and correct telescoping movement of the extensible member without permitting lateral movement thereof. The actuating mechanism for the extensible boom member will now be explained.

A pair of parallel supporting bars 3l are provided at their left hand ends as viewed in the drawing with tongues 38 extending in and secured to supporting iittings 39 mounted in the plate 2l of the xed boom member I4. The supi porting bars 3'! have mounted between them a cylinder $3 with the heads at the opposite ends of the cylinder iixedly secured to the bars. The cylinder vAll mounts a sliding piston il from the opposite sides of which project piston rods 42 and 43 of the same diameter, wherefore the effective pressure areas on the opposite sides of the piston are the same.

The piston rods 32 and 43 extend through the cylinder heads at the opposite ends of the cylinder and said heads are provided with ports t4 and 35 constituting inlet and exhaust ports depending upon the direction of movement of the piston in the cylinder. It will be understood that the ports 44 and 25 are suitably connected by a supply and exhaust circuit to a source of pressure fluid and that said circuit includes a suitable control valve for selectively causing the ports Il and 45 to be inlet or exhaust ports.

The piston rods l2 and 53 have secured to their outer ends, respectively, pairs of sheaves i--S and lll, as shown in Fig. 7. The cylinder [i6 on its upper side and intermediate the supporting bars 3l has secured to it a pair of longitudinally spaced sheaves 48. The supporting bars 3"! and cylinder lll extend through the xed boom member and into the extensible boom member. The lower plate 313 of the extensible boom member has secured to its inner side an anchoring lug 43 which supports oppositely extending pairs of I-bolts 56 as shown in Fig. 5a. The I-bolts 5G are individually adjustable and may be locked in adjusted position by suitable means such as the lock nuts shown in the drawings.

An actuating cable 5l is connected to one of the left hand pair of I-bolts 50 and extends therefrom around one of the sheaves il from whence it passes around the leit hand sheave i3 and thence around the other sheave il from where it extends and is secured to the other I-bolt 5G of the left hand pair of -bolts.

An actuating cable 52 is connected to one of the I-bolts of the right hand pair and extends therefrom around one of the sheaves d'5 and thence around the right hand sheave i3 as viewed in Fig. 7, from whence it passes around the other sheave 66 and returns and is secured to the other I-bolt of the right hand pair of I-bolts. It will be understood that the adjustability of the I-bolts is for the purpose of taking up slack in the actuating cables i and 52 and putting tension thereon.

Inasmuch as the cylinder fifi is stationarily mounted within the xed boom member i@ it will be seen that when the control is set by the operator so pressure uid is admitted to the cylinder 40 through the port 45 and exhausted therefrom through the port 4, the piston il will move from the position shown in Fig. fl toward the right to cause an extension or" the piston rod l2 beyond the right hand cylinder head and to draw the piston rod 43 into the cylinder. The extension of the piston rod 42 acting through the sheaves l on the cable 52 will cause the extensible boom meinber Il to move outwardly of the fixed boom member i4 and be extended with respect thereto. This movement of the extensible boom member il is permitted by the movement of the piston rod d3 into the cylinder, since the actuating cable 5i passing around the sheaves il plays out to allow such movement of the extensible boom member.

It will be seen that the extending movement of the boom member il is under the control of the cable 5i which permits the outward movement of the boom member il in equal proportion to the production of such movement by the cable 52.

Consequently the extensible movement of the boom member Vl is always a controlled and steady movement.

It will be understood that when it is desired to move the boom member Il' from an extended position to a retracted position within the fixed boom member M, the control valve is set by the operator so pressure fluid is admitted to the cylinder lll through the port 44 and exhausted therefrom through the port 45 so that the piston 41| moves toward the left in the cylinder 40 as viewed in the drawings. This movement of the piston, of course, causes the actuatingcable 5l to produce the retracting movement of the boom member Il while the cable 52 permits such movement.

It will be noted that the amplitude of movement of the piston 4I to extend or retract the boom member Il is fractional as compared to the actual movement of said member. As illustrated, the movable boom member IT has a twoto-one movement with respect to the piston 4I but it will be understood that this ratio between boom movement and piston movement can be varied by changing the arrangement of the sheaves and cables.

Although a preferred embodiment of the invention has been illustrated and described herein, it will be understood that the invention is susceptible of various modifications and adaptations within the scope of the appended claims.

Having thus described my invention, I claim:

1. In an extensible telescoping boom of the type having a fixed boom member and an extensible boom member in telescopic relationship with the fixed member, actuating mechanism for said extensible boom member and comprising a power operated device including a part located within and having xed relationship with respect to said fixed boom member and an elongated L' movement producing part extending through and movable relative to said first part, longitudinally spaced sheaves mounted on said rst part, sheaves carried by the opposite ends of said movement producing part, and actuating cables secured to therinterior of said extensible member and reeved around said sheaves so that movement of said movement producing part imparts to said extensible boom member amplied extending or retracting movements.

2. In an extensible telescoping boom of the type having a xed boom member and an extensible boom member in telescopic relationship with the fixed member, actuating mechanism for said extensible boom member and comprising a cylinder xedly mounted in said xed boom member and extending into said extensible boom member, a piston movable in said cylinder and having piston rods projecting from its opposite sides and extending beyond the opposite ends of said cylinder, sheaves mounted on said cylinder, sheaves carried by the ends of said piston rods, and actuating cables secured to the interior of said extensible boom member and reeved around said sheaves to cause piston movement to impart to the extensible boom member amplified extending and retracting movements.

3. In an extensible telescoping boom of the type having a fixed boom member and an extensible boom member telescoping relative to the fixed member, `parallel supporting members nxedly mounted within the mixed boom member, a cylinder located between and secured to said supporting members, a piston movable in said cylinder and having piston rods projecting from the opposite sides thereof and extending beyond the ends of said cylinder and located between said supporting members, a pair of longitudinally spaced sheaves secured to said cylinder, a pair of spaced sheaves mounted on the end of each piston rod, and a pair of actuating cables each having its ends secured interiorly to the extensible boom member, said actuating cables being reeved respectively around the spaced sheaves at the end of one of the piston rods and around one of the sheaves carried by the cylinder, wherefore piston movement in either direction is imparted to said extensible boom member in an amplified ratio of two-to-one.

4. In an extensible telescoping boom or the type having a fixed boom member and an extensible boom member telescoping within the fixed member, parallel supporting members xedly mounted within the xed boom member, a cylinder located between and secured to said supporting members, a piston movable in said cylinder` and having piston rods of equal diameter projecting from the opposite sides thereof and extending beyond the ends of said cylinder and located between said supporting members, a pair of longitudinally spaced sheaves secured to said cylinder, a pair of spaced sheaves mounted on the end of each piston rod, a pair of actuating cables reeved respectively around the spaced sheaves at the end of one of the piston rods and around one of the sheaves carried by the cylinder, and adjustable means for connecting the ends of said cables to the interior of the extensible boom member wherefore piston movement in either direction is imparted to said extensible boom member in an amplied ratio while said adjustable means provides for the taking up cf slack or play in said cables.

5. In an extensible telescoping boom of the type having` a fixed boom member and an extensible boom member in telescopic relationship with the -iixed boom member, actuating mechanism for said extensible boom member and comprising a cylinder iixedly mounted in said fixed boom member and extending into said extensible boom member, a piston movable in said cylinder and having piston rods projecting from its opposite sides and extending beyond the opposite ends of said cylinder, said piston rods having the same diameters wherefore equal lengths or said rods will displace equal volumes of fluid in said cylinder, sheaves mounted on said cylinder, sheaves carried by the ends of said piston rods, and actuating cables secured to the interior of said extensible boom member and reeved around said sheaves to cause piston movement to impart to the extensible boom member amplified extending and retracting movements.

References Cited in the file of this patent UNITED STATES PA'IENTS Number' Name Date 326,336 Sandberg et al Sept. 15, 1835 484,664 Mesta Oct. 18, 1892 1,845,304 Zied June 29, 19.20 1,390,837 Stubbe Sept. 13, 1921 1,898,369 Hohmann et al Feb. 21, 1933 2,196,649 Waite Apr. 9, 1940 2,261,930 Abbe Nov. 11, 1941 2,382,299 Deiters Aug. 14, 1945 2,510,636 Johnson June 6, 1950 2,541,045 Ferwerda et al Feb. 13, 1951 

